Trocar



W. B. WESCOTT.

TROCAR.

APPLICATION FILED NOV. 28, 1919.

Patented Aug. 3, 1920.

FIG. 2

\ glam- FIG. 1

UNITED STATES PATENT OFFICE.

WILLIAM BURTON WESCOTT, OF WELLESLEY, MASSACHUSETTS, ASSIGNOR TO KALMUS, COMSTOCK & WESCOTT, INCL, OF BOSTON, MASSACHUSETTS, A COR- PORATION OF MASSACHUSETTS.

TROGAR.

Specification of Letters Patent.

Patented Aug. 3, 1920.

To all 10. mm it may concern:

Be it known that 1, WILLIAM BURTON \Vnsco'rr, citizen of the United States of America, and resident of \Vellesle ,in the county of Norfolk and State 0 Massachusetts, have invented new and useful Improvements in Trocars, of which the following is a specification.

This invention relates to a trocar intended particularly for obtaining blood from food animals at the time of slaughter, free of contamination and suitable for human food or for therapeutic purposes. The invention which consists in the features hereinafter described and particularly pointed out in the claims, comprises certain improvements upon and modifications of the lnventions shown in applications for Letters Patent of the- United States filed by me April 8, 1919, Serial Number 288,641; June 14, 1919, Serial Number 304,317 and August 4, 1919, Serial Number 315,187.

In the accompanying drawings which illustrate the invent1on- Figure 1 is a longitudinal sectionof the instrument, partly in elevation;

Fig. 2 is a side elevation of the instrument viewed at right angles to Fig. 1;

Fig. 3 is a top end view showing the blades in closed position; and

Fig. 1 is a top end view showing the blades in open position.

1 is the cannula, the forward partof which flares or spreads in the direction of the edges of the blade, as indicated at 1 (Fig. 1), and tapers or narrows in the direction of the flat sides of the blade, as indicated at 1 (Fig. 2), thus forming a substantiall oval or flattened end adapted readily to ollow the blade of the instrument into the cut and at the same time to afford ample room for the swinging of the levers presently to be described.

The perforator blade at the forward end of the cannula is divided lengthwise into two sections2 and 2 which are fixed respectively to the forward ends of two crossed levers 3, 3 pivoted to the cannula.

The levers 3, 3 are housed within the cannula and pivoted scissors-fashion on pin 4, the ends of which are lodged in open sockets formed in two bosses 4 fixed to the inner walls of the cannula. The lower or rear end through a hole in the cannula wall. Each operatlng member 5 is engaged by the under side of a handle 6. The two handles 6, 6 are pivoted to opposite sides of the cannula by plvot pins 8, which extend between lugs or ears 9, 9, carried by a ring 7 encircling the cannula. The levers 3 are normally and yieldingly urged apart by springs 10. Consequently the blade sections 2, 2, and the handles 6, 6, are also normally held in separated or open position.

The forward end of each lever 3 carries a cap 11, at the base of the blade section, adapted to fit over and cover the end of the cannula when the levers are in closed posit on. On the under side of each cap 11 is a rib or tenon 11 which fits into a correspond lng notch 11 formed inthe end of the cannula wall, thus providing mutually engaging guldmg members which hold the blade sections and levers in proper relation to the cannula in all positions. The cap 11 and rib 11*" may both be made integrally with the blade section.

The cleft or line of division between the two blade sections preferably opens through the edge of the blade somewhat to the rear of the point as best shown in Fig. 1 instead of through the point, thus insuring a smoother and more effective perforating point for making the entering penetration than if the extreme point of the blade were divided. In order to keep the two blade sections in accurate alinement with a practically continuous cutting edge when the blade sections are closed together, one section is made with a projection or feather 12 which fits into a corresponding recess or groove 13 in the opposite section. This holds the sections rigidl in place and prevents side play between t 1e sections when the sections are closed together.

In operation, when the user presses the handles 6, 6, together, the levers 3 and blade sections will be closed as indicated by broken lines in Fig. 1 and while in closed position the instrument is thrust into the animal to be bled. By reason of the width of the blade and the taper of the cannula walls toward the fiat of the blade the instrument may be inserted through the hide forming its own initial opening; or, a slit may first be cut through the hide in the ordinary way and then this instrument be inserted into the region of a large blood vessel. In either case the caps 11 will prevent the entrance of any contaminating matter into the cannula. When the instrument is in place in the animal the operator merely releases the handles, whereupon the blade sections 2 and 2 will be opened or separated by spring 1( as shown in full lines in Fig. 1 thereby widening the cut, opening the end of the cannula to the flow of blood from the enlarged cut thus formed at the end of the perforation, and forcing the projecting heels at the base of the blade sections, which now act as retaining hooks, into the tissues surrounding the instrument thus holding it in place in the animal. lVhen it is to be withdrawn the user again presses the handles 6, 6, together, thereby retracting the retaining hooks and releasing the instrument for removal.

It will be understood that the lower or rear end of the cannula 1 will be connected by a pipe or tube to a suitably closed vessel for receiving and holding the blood.

The leversa-nd blades may be removed from the cannula for sharpening, or for cleaning the parts by springing the fingers or hooks 5 inward through the holes and then slipping the levers endwise through the forward end of the cannula, as the .sockets 4 which support the pivot pin 4, are open on the side toward the forward end of the cannula.

I claim:

1. A trocar comprising a cannula, a perforator blade at the forward end of the cannula divided into two sections, and a pair of levers pivoted to the cannula, the two blade sections being fixed respectively to the forward ends of the two levers.

2. A trocar comprising a cannula, a perforator blade at the forward end of the cannula divided into two sections, and a pair of levers housed within the cannula and pivoted thereto, the two blade sections being fixed respectively to the forward ends of the two levers.

3. A trocar comprising a cannula, a perforator blade at the forward end of the cannula divided into two sections, and a pair of levers pivoted to the cannula, the two blade sections being fixed respectively to the forward ends of the levers, each blade section having a projecting heel adapted to serve as a retaining hook when the blade sections are separated.

4. A trocar comprising a cannula, a perforator blade at the forward end of the cannula divided into two sections, and a pair of levers housed within the cannula and pivoted thereto, the two blade sections being fixed respectively to the forward ends of the two levers, operating members on the rear ends of the levers projecting through the walls of the cannula and handles outside of the cannulafor actuating the levers throu h the operating members.

5. A trocar comprising a cannula, a per-- forator blade at the forward end of the cannula dividedinto two sections, and a pair of levers housed within the cannula and pivoted thereto, the two blade sections being fixed respectively to the forward ends of the two levers, fingers 0n the rear ends of the levers projecting through the walls of the cannula, and handles pivoted to the outside of the cannula to engage said fingers and actuate the levers.

6. A trocar comprisinga cannula, a perforator blade at the forward end of the cannula divided into two sections, and a pair of levers pivoted to the cannula, the two blade sections being fixed respectively to the forward ends of the levers, and yielding means normally urging the blade sections apart.

7 A trocar comprising a cannula, a perforator blade at the forward end of the cannula divided into two sections, and a pair of levers pivoted to the cannula, the two blade sections being fixed respectively to the forward ends of the levers, each blade section having a projecting heel adapted to serve as a retaining hook when the blade sections are separated, and yielding means normally urging the blade sections apart.

8. A. trocar comprising a cannula, a perforator blade at the forward end of the cannula divided into two sections, a pair 'of levers pivoted to the cannula, the two blade sections being fixed respectively to the forward ends of the two levers, and caps carried by the levers adapted to cover the end of the cannula when the levers are in closed position.

9. A trocar comprising a cannula, a perforator blade at the forward end of the cannula divided into two sections, a pair of levers pivoted to the cannula, the two blade sections being fixed respectively to the forward ends of the two levers, and caps carried by the levers adapted to cover the end of the cannula when the levers are in closed position, and mutally engaging guiding members between the end of the cannula and the ends of the levers.

10. A trocar comprising a cannula, oval at its forward'end, a perforator blade at the forward. end of the cannula disposed in the plane of the longer axis of the oval and divided .into two sections, and a pair of levers pivoted to the cannula to swing in the direction of the longer axis of the oval, the two blade sections being fixed respectively to the forward ends of the two levers.

Signed by me at Boston, Massachusetts, this 25th day of November, 1919.

WILLIAM BURTON WESCOTT. 

